For the first three days of July 1863, the fate of the Union hung in the balance as a bloody battle played itself out in a small Pennsylvania town named Gettysburg.

On the offensive were the 70,000 rebels of Gen. Robert E. Lee's Army of Northern Virginia, fresh from their victory at Chancellorsville in central Virginia, and now determined to take the war onto Northern soil. Defending was the 93,000- man Army of the Potomac under the command of newly appointed Gen. George G. Meade.

All told, over 11,000 men would be killed, 5,000 alone in the final Confederate attack later immortalized as Pickett's Charge. Another 40,000 would be wounded, captured or missing. The biggest casualty, however, would be the South's hope to win militarily, thus cementing forever Gettysburg's reputation as the decisive battle of the Civil War.

For more than a decade now, both the battlefield and the town have been getting ready for the 150th anniversary, or sesquicentennial. The results are impressive: an expansive new visitor center, the restoration of the landscape to 1863 appearances and the elimination of an eyesore observation tower. As for the town, well, it was just named "America's Best Small Town" by Smithsonian Magazine.

So, whether you've never been to Gettysburg or haven't been there in years, 2013 is definitely the year to march on in. But be forewarned: Gettysburg's annual visitor total of one million is expected to quadruple. It will be especially crowded during the official commemoration period, June 28-July 7.

The museum

A new, unobtrusively situated visitor center features the Gettysburg Museum of the Civil War, a meandering, 11-gallery feast of artifacts (more than 300,000 of them, including Lee’s field desk, cot and stove), plus mini theaters and touch screens. It’s all designed to pull modern-day visitors back into the 1860s, starting with the issue of slavery, the election of 1860 and the outbreak of hostilities. The battle itself naturally receives its full measure of devotion, including General Pickett’s wry explanation of what went wrong (“I’ve always thought the Yankees had something to do with it”), and the narrative continues through Lee’s surrender at Appomattox, Reconstruction and efforts to preserve the battlefield.

The second floor of the visitor center is the new home of "The Battle of Gettysburg" cyclorama, which, at 377 feet in length and 42 feet in height, is the largest painting in the world. The 360-degree panorama, which depicts Pickett's Charge in meticulous detail, was executed in 1883-84 in the Parisian studio of Paul Philippoteaux and first displayed in Boston.

A six-year, $15 million restoration included the addition of a foreground diorama, littered with faux artifacts, adding to the verisimilitude. Access to the viewing platform is preceded by a screening of "A New Birth of Freedom," a 22-minute documentary narrated by Morgan Freeman. Once inside, however, move quickly: you only get 15 minutes before the next group arrives.

The battlefield

All told, Gettysburg National Military Park encompasses more than 6,000 acres and includes more than 1,300 monuments and memorials. Seeing it, therefore, requires transportation, with most visitors opting for the 24-mile self-guided driving tour. Signboards and audio boxes explain various aspects of the conflict at 16 designated stops, or you can purchase the auto tour CD in the gift store for $19.95. Free, ranger-led walking tours of select parts of the battlefield (from 20 minutes to two hours in length) are offered throughout the day, or you can hire a licensed guide to ride along with you ($65 for two hours, 1-6 people. Additional transportation options include horseback and segway.

However you choose to see it, make time to walk some of the more dramatic terrain, particularly Little Round Top, the Devil's Den, and the High Water Mark along Cemetery Ridge. The roof of the white-marble Pennsylvania Memorial, Gettysburg's largest, provides a panoramic view of the main battlefield, while the 3,850 Union graves in the National Cemetery, half of them marked "unknown," provides a sobering reminder of the human cost of glory.

The Address

On Nov. 19, 1863, before a crowd of some 10,000, President Abraham Lincoln dedicated the still-unfinished Soldiers National Cemetery in a mere 256 words that he, himself, thought "the world will little note." The Gettysburg Address, however, turned out to be the most famous speech in American history, and since 2009, its story has been told at the three-story former residence of local lawyer David Wills, who had invited the president to speak (never imagining that he would accept) and put him up the night before. Artifacts, signboards and dioramas contextualize the event, debunking the persistent myths that it was written on the back of an envelope and was not applauded. The Rococo bedroom (Mrs. Wills') where Lincoln slept after putting the finishing touches on his speech has been preserved.

If you go

Gettysburg is 225 miles southwest of New York City via I-78, I-81 and U.S. Route 15.

GETTYSBURG NATIONAL MILITARY PARK MUSEUM & VISITOR CENTER 1195 Baltimore Pike; 717-334-1124, nps.gov/gett. Admission to the visitor center (open 9 a.m.-6 p.m. between Memorial Day and Labor Day) is free, as is access to the battlefield itself (open from dawn to one hour after sunset). Entrance to the museum and cyclorama costs $12.50 for adults and $8.50 for children ages 6-12.

RE-ENACTMENTS will take place July 4-7 at 1085 Table Rock Rd., about three miles north of town. Daily admission ($35 ages 13 and older, $15 ages 6-12) includes a full day's worth of field demonstrations, living history exhibits, lectures and two hourlong battles (717-338-1525; gettysburgreenactment.com).

EISENHOWER NATIONAL HISTORIC SITE Gettysburg's other marquee attraction is the Eisenhower National Historic Site, Ike and Mamie's post-presidency home and farm (nps.gov/eise). A regiment of lesser attractions, most of them related to the battle, includes historic houses, museums (including wax), dioramas, theatrical performances, themed walking tours and ghost tours.